CVE detail

CVE-2021-0258 — CVE-2021-0258

Published 2021-04-22 · Modified 2026-06-17 · Vendor juniper · Product junos · Source nvd
MEDIUM
severity
CVSS-derived band
5.9
CVSS v3
0–10 scale
0.0065
EPSS probability
exploitation probability, 30d
48.0%
EPSS percentile
percentile vs all CVEs
NOT LISTED
CISA KEV
known exploited catalog

Description

A vulnerability in the forwarding of transit TCPv6 packets received on the Ethernet management interface of Juniper Networks Junos OS allows an attacker to trigger a kernel panic, leading to a Denial of Service (DoS). Continued receipt and processing of these transit packets will create a sustained Denial of Service (DoS) condition. This issue only occurs when TCPv6 packets are routed through the management interface. Other transit traffic, and traffic destined to the management interface, are unaffected by this vulnerability. This issue was introduced as part of a TCP Parallelization feature added in Junos OS 17.2, and affects systems with concurrent network stack enabled. This feature is enabled by default, but can be disabled (see WORKAROUND section below). This issue affects Juniper Ne

Remediation

vendor remediation guidance

The following software releases have been updated to resolve this specific issue: Junos OS 17.2R3-S4, 17.3R3-S9, 17.4R2-S11, 17.4R3-S2, 18.1R3-S11, 18.2R3-S5, 18.3R2-S4, 18.3R3-S3, 18.4R2-S5, 18.4R3-S4, 19.1R2-S2, 19.1R3, 19.2R1-S5, 19.2R2, 19.3R2-S4, 19.3R3, 19.4R1-S3, 19.4R2, 20.1R1, and all subsequent releases.

workarounds

Disable TCP Parallelization: set system kernel-smp-features disable-concurrent-network-stack

ProductVulnerable rangeFixed versionAdvisory
Juniper Networks Junos OS>=17.3<17.3R3-S917.3R3-S9advisory ↗
Juniper Networks Junos OS>=17.4<17.4R2-S11, 17.4R3-S217.4R2-S11, 17.4R3-S2advisory ↗
Juniper Networks Junos OS>=18.1<18.1R3-S1118.1R3-S11advisory ↗
Juniper Networks Junos OS>=18.2<18.2R3-S518.2R3-S5advisory ↗
Juniper Networks Junos OS>=18.3<18.3R2-S4, 18.3R3-S318.3R2-S4, 18.3R3-S3advisory ↗
Juniper Networks Junos OS>=18.4<18.4R2-S5, 18.4R3-S418.4R2-S5, 18.4R3-S4advisory ↗
Juniper Networks Junos OS>=19.1<19.1R2-S2, 19.1R319.1R2-S2, 19.1R3advisory ↗
Juniper Networks Junos OS>=19.2<19.2R1-S5, 19.2R219.2R1-S5, 19.2R2advisory ↗
Juniper Networks Junos OS>=19.3<19.3R2-S4, 19.3R319.3R2-S4, 19.3R3advisory ↗
Juniper Networks Junos OS>=19.4<19.4R1-S3, 19.4R219.4R1-S3, 19.4R2advisory ↗

References

cvedb.io · NVD · CISA KEV · FIRST EPSS · vendor advisories (CVE Program List v5). Informational only, no warranty — verify every remediation against the vendor advisory before acting on it. This product uses data from the NVD API but is not endorsed or certified by the NVD, CISA, FIRST.org or any vendor named. CVE® is a registered trademark of The MITRE Corporation.